I've rented recently from DOLLAR in LAS at the airport. As suggested, make sure you join FASTLANE for the reasons mentioned.

My last experience at the airport was so-so - not great, not too bad. After you get off the shuttle, look around for an outdoor counter partially under the white tent. This was the FASTLANE line last time I rented a few months ago.

With DOLLAR in LAS I always rent a FULL SIZE hoping for a Dodge Magnum but have yet to get anything but a Ford Taurus at the airport. At the DOLLAR desks at the hotels I've had much better luck getting an upgrade from Full Size.